1. Field of the Invention
The present invention relates to a liquid drop discharger and a method of discharging a liquid drop, a test chip processor and a method of processing a test chip using the liquid drop discharger, a printer device, a printing method, a method of producing an organic electroluminescent panel, a method of forming a conductive pattern, and a method of producing a field emission display.
2. Description of the Related Art
A liquid drop discharger, typified by an inkjet head of, for example, a printer, discharges liquid drops from a predetermined discharge opening by subjecting a liquid chamber containing a liquid, such as ink, to some sort of pressure. Various means for subjecting the liquid chamber to pressure have been proposed. For example, means having a structure using a piezoelectric device (piezo type) and means having a structure making use of a film-boiling phenomenon caused by a heat-generating device (bubble type) are widely used as liquid drop dischargers. In addition, means for discharging a liquid by moving a wall (film) of a liquid chamber by an electromagnetic force by a very small amount has been proposed (refer to, for example, Japanese Unexamined Patent Application Publication No. 2001-270104 (Patent Document 1)).
Such liquid drop dischargers are capable of discharging drops of a desired liquid onto predetermined locations precisely. Therefore, they are used not only when using a printer device, but also, for example, when disposing a liquid containing DNA onto each location of a chip in producing desoxyribonucleic acid (DNA) chip or in analyzing DNA, or when disposing a fluorescent material or a light-emitting material onto each pixel location during manufacturing of a display. Accordingly, they are beginning to be used in a wide range of applications. This has caused a demand for a more desirable liquid drop discharger that is used in such various applications including its use in a printer device.
A piezo liquid drop discharger such as that mentioned above is small and highly reliable, but has a high drive voltage. This demerit is overcome by a method of reducing an applied voltage itself by forming piezoelectric devices and electrodes in multiple layers. However, this method requires a high voltage of approximately 30 V and gives rise to another demerit that costs of the discharger are increased.
A liquid drop discharger of a type that uses a magnet in a drive circuit (such as the type disclosed in, for example, Patent Document 1 in which the wall of a liquid chamber is moved by electromagnetic force) has poor responsiveness due to an increase in inductance when the operating frequency is increased.
There is a demand that both types of liquid drop dischargers discharge liquid drops in accordance with a high-frequency drive signal, that is, to discharge individual liquids at a high speed.
When the bubble liquid drop discharger tries to discharge a liquid containing an organic material, such as DNA or protein, the organic material is decomposed as a result of being exposed to high temperature and pressure, so that the discharger cannot properly discharge the material to be discharged.
When handling such an organic material, it is necessary to frequently clean and replace a nozzle, such as a discharge opening, a liquid chamber, and a liquid supply path. However, since, in the piezo liquid drop discharger, a piezoelectric device is connected directly to a diaphragm or is connected to the diaphragm by a fine mounting technology, it is difficult to separate the piezoelectric device and replace the nozzle. The piezoelectric device and the nozzle may be constructed so that they can be replaced together, but the portions to be replaced are expensive and re-connection of an electrical wiring is required. Therefore, this structure is not a practical structure.